Hi!
If you are new to web services and is going to write a
SOAP web service client, then the easiest and quickest thing to do is to ignore any APIs and instead generate client artifacts from a WSDL.
Take a look at the tutorials at NetBeans:
http://netbeans.org/kb/trails/web.html
NetBeans is the free
IDE that has best web service tooling.
Best wishes!